Liverpool signed Italy striker Mario Balotelli from AC Milan for $26.5 million on Monday, taking a calculated gamble on a headline-grabbing player known as much for his controversies as his goals.

Nineteen months after ending a 2 1/2-year spell with Manchester City to play for his boyhood club, Balotelli will return to the English Premier League as a replacement for Luis Suarez -- another of world football's talented but disruptive stars.

"I'm happy to be back because I left England and it was a mistake," Balotelli said. "I wanted to go to Italy but I realized it was a mistake."

Balotelli, who has signed what Liverpool said is a "long-term deal," has already trained at his new club and will attend the team's Premier League game against City at Etihad Stadium later Monday. He wasn't registered in time to play.

Liverpool has been looking to strengthen its strikeforce after selling Suarez to Barcelona for $130 million but left it to the last week of the transfer window to secure one of the summer's most high-profile and intriguing signings.

During his time at City, in which he won the league title, Balotelli was sent off four times, threw a dart at a youth-team player and was involved in an incident that saw fireworks explode in his bathroom. Days before news of the fireworks incident emerged, Balotelli had revealed a T-shirt under his City jersey with the question, "Why Always Me?" after scoring in the team's 6-1 win over Manchester United.

Balotelli, with his physique, technical ability and qualities as a finisher, is one of the world's best strikers and, at 24, the best times of his career could still lie ahead of him. At Milan, he scored 26 goals in 43 league matches and he is the Italian national team's top striker, scoring 13 goals in 33 games.

But with trouble always seeming to follow him, some are questioning whether Balotelli is worth the risk for Liverpool, which has fostered a strong team spirit under manager Brendan Rodgers that helped it finish second in the Premier League last season. Jose Mourinho described Balotelli as "unmanageable" during their time together at Inter Milan, which the striker left in 2010 to join City.

"He knows himself this is probably is last chance," Rodgers said. "Mario is someone we can improve both as a footballer and as a person."

Rodgers, however, got the best out of Suarez and current first-choice striker Daniel Sturridge, who both had turbulent pasts before arriving at Anfield. Sections of the British media have reported that Balotelli has had to agree to behaviour clauses being included in his contract with Liverpool.

"I believe we have the infrastructure, culture and environment to get the best out of him and help him achieve his true potential," Rodgers said. "We are a strong group here, committed to hard work and he will benefit from being around it.

"I am looking forward to working with him and helping him learn more, improve and progress as a player.

Rodgers' attempts to bring in a striker has seen him look at France forward Loic Remy of Queens Park Rangers, whose switch to Anfield broke down at the last minute, and former Barcelona, Inter Milan and Chelsea star Samuel Eto'o. Last month, during Liverpool's tour of the United States, Rodgers was linked with a bid for Balotelli but said "I can categorically tell you that he will not be at Liverpool."

The U-turn was completed on Monday.

"This transfer represents outstanding value for the club and I think we have done a really smart piece of business here," Rodgers said. "There is no doubting Mario's ability; he is a world-class talent and someone who, for such a young age, has vast experience of playing at the very highest level."

Asked what his targets at Liverpool were, Balotelli said: "I want to take this team to the Champions League."